/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicVertexSkinWeightsAttribute.h
Set the element at a given index
template<typename BoneIndexType, typename BoneFloatWeightType> void SetValue ( int VertexID, const [TArray](API\Runtime\Core\Containers\TArray)< BoneIndexType > & InBones, const [TArray](API\Runtime\Core\Containers\TArray)< BoneFloatWeightType > & InWeights, int32 InNumEntries )